I offered my meaning on the thread I started - Olympic Closing - anyway, here goes: Being Italy and Roman Catholic (mainly) I think it was supposed to represent the Brides of Christ and Peace (they assembled into a dove at the end). Makes sense to me.
I think the NBC announcers said that the brides represented hope. I guess when one thinks of a bride then you're supposed to think of white dress and purity and bride's hope for her future, but that was just my take on it. Then when they assembled into the dove I just figured it meant hope, peace, and the rays of light they carried were the Olympic Spirit being carried on. Maybe I'm off my rocker, but that's what I took from the announcer's comments and the images of all those women in white. I don't think it had anything to do with religion although that's what I thought at first too.